A. Field
The invention concerns an improved semi-automatic rifle.
B. Brief Summary of the Invention
A semi-automatic rifle is provided with a gas intake recock device which allows for the automatic recock of the rifle when firing, i.e. which makes it possible to extract the cartridge casing out of the barrel chamber and to eject it on the one hand, and to feed a new cartridge into said chamber.
The recock device comprises a gas cylinder whose chamber is connected to the bore of the barrel via a vent hole and which contains a piston which makes contact with the moving parts and which can control the recock of the rifle.
The working principle of a semi-automatic rifle is based on the recovery of part of the gases, emitted as a result of the explosion of the cartridge powder, by the opening between the barrel and the gas cylinder, before the bullet of said cartridge has left the barrel, in other words high-pressure gases.
When the gases get into contact with the piston, they produce a shock effect which thrusts the moving parts to the rear and they also compress the spring placed behind the moving parts. The moving parts are connected to the locking device of the rifle and their backward movement guarantees the recock of the rifle.
The moving parts are stopped in their movement as they make contact with a shock absorber unit.
Due to the violent shock with the shock absorber, the moving parts tend to seriously rebound, which results in an immediate and very violent return of the moving parts.
Said rebound may result in malfunctions in the feeding of the next cartridge or in keeping the moving parts in their open position when the last cartridge is being fired.
In order to prevent said malfunctions, the moving parts are provided with a floating mass.
This floating mass is thrust to the rear simultaneously with the other moving parts as a result of the action of the piston, but it is free to follow its course after the other moving parts have been stopped as a result of the contact with the shock absorber.
Due to its inertia, the floating mass continues the backward movement and hits the other moving parts. As a result, the moving parts as a whole will be kept in the above-mentioned open position for a very brief moment so as to allow for the automatic ejection of the used cartridge casing and for the feeding of a new cartridge from the loader.
After said calculated delay, the return spring pushes all the moving parts to the front of the rifle again so as to load a new cartridge in the barrel chamber and to reassume said closed position, thus having the option to fire an additional shot.
The invention aims to simplify the automatic recock device and to improve its efficiency by reducing the weight at the front of the rifle so as to guarantee smoother movements for the rifle.
This aim is reached according to the invention by means of an improved semi-automatic rifle comprising a frame; a barrel; a sliding guide mounted in the frame and forming one piece with breech bolts which make it possible to control the recock and the locking of the rifle; an automatic recock device comprising a piston mounted in a gas cylinder whose chamber is connected to the bore of the barrel via a vent hole, whereby the piston makes contact with the head of a sliding guide which is connected to the sliding guide and which is mounted in a sliding manner on a guiding rod which forms one piece with the frame and which is mainly parallel to the axis of the barrel; a floating mass through which the guiding rod passes and which is mounted in a sliding manner in the axial direction of the guiding rod between two sides of a housing in the head of the sliding guide; and a return spring mounted round the guiding rod and situated between the frame and the floating mass, characterized in that the head of the sliding guide is at least partially made of technical thermoplastic material.
On the one hand, the selection of the technical thermoplastic material makes it possible to improve the shock absorbing capacities.
On the other hand, the low density of this material in comparison with the materials that are presently used makes it possible to reduce the general weight of the moving parts as a whole and thus the total weight of the rifle, and to also reduce the weight of the front part of the rifle, since the head of the sliding guide is situated in the front of the rifle.
Knowing that the relation between the weight of the head of the sliding guide and the weight of the moving parts is preferably a constant, the reduction of the weight of the head of the sliding guide also allows for the reduction of the weight of the floating mass which is part of the moving parts as a whole, which thus allows for an additional reduction in weight of the front part of the rifle and a more favorable relation between the weight of the moving parts and the weight of the floating mass.
According to a particular characteristic of the invention, the return spring is formed of a flat wire and not of a round wire, as is the case in most known semi-automatic rifles.
Thanks to the use of a flat wire, the working characteristics are improved, which implies that there will be less slackening. Moreover, the risk for the windings of the spring to be superimposed during the compression is excluded, and hence the break risk is reduced.
The flat wire also makes it possible to use the outer surface of the return spring as a sliding guide for the floating mass. This solution offers the chance to eliminate the guides and springs of the floating mass that are presently separate elements and to thus also reduce the weight of the front of the rifle even further.